It benefits the poor by allocating resources as efficiently as possible. If there is someone who is poor enough that they need help from society/the government, it would be much more effective to transfer money directly to the, rather than very very poorly (probably regressively in fact) target that help by having the public subsidize parking on their block.

They would rather have the $100 in efficient redistribution rather than the government spend $100 so that they can benefit by $1.